Heavy-duty engine and vehicle fuel efficiency; Spark-ignition reciprocating or rotary internal combustion piston engines. (HS code(s): 8407); Compression-ignition internal combustion piston engines (diesel or semi-diesel engines). (HS code(s): 8408); Tractors (other than tractors of heading 87.09). (HS code(s): 8701); Motor vehicles for the transport of ten or more persons, including the driver. (HS code(s): 8702); Motor cars and other motor vehicles principally designed for the transport of persons (other than those of heading 87.02), including station wagons and racing cars. (HS code(s): 8703); Motor vehicles for the transport of goods. (HS code(s): 8704); Special purpose motor vehicles, other than those principally designed for the transport of persons or goods (for example, breakdown lorries (wreckers), crane lorries (mobile cranes), fire fighting vehicles, concrete mixer lorries (concrete-mixers), road sweeper lorries (road sweepers), spraying lorries (spraying vehicles), mobile workshops, mobile radiological units). (HS code(s): 8705); Quality (ICS code(s): 03.120); Air quality (ICS code(s): 13.040); Test conditions and procedures in general (ICS code(s): 19.020); Road vehicles in general (ICS code(s): 43.020); Internal combustion engines for road vehicles (ICS code(s): 43.060); Commercial vehicles (ICS code(s): 43.080); Passenger cars. Caravans and light trailers (ICS code(s): 43.100)

Improvements for Heavy-Duty Engine and Vehicle Fuel Efficiency Test Procedures, and Other Technical Amendments; (47 page(s), in English)

Proposed rule - The National Highway Traffic Safety Administration (NHTSA) is proposing minor technical amendments to the test procedures for heavy-duty engines and vehicles to improve accuracy and reduce testing burden. These amendments affect the certification procedures for fuel efficiency standards and related requirements. These proposed amendments increase compliance flexibility, harmonize with other requirements, add clarity, correct errors, and streamline the regulations. Given the nature of the proposed changes, NHTSA does not expect either significant environmental impacts or significant economic impacts for any sector.